Checked earth from sensors to ECM and all good, but earth wire at sensors to rear earth connection shows 0.7 - 1.1 ohms difference. Is this ok and if not what would cause it?

Checked water pump, trans cooler, and calibrated temp sensor for the engine warning light. The check light comes on and goes off when I dissconnect this temp sensor. Calibrated to 95degrees C (203F) and it comes on after a hard run but the dash temp shows 160F and this sender is in the same water channel is it not?

JimN there are many Mastercrafts (also Malibu- made locally, Nautique, Supra, Mobius,etc) over here, its just the dealer will not support boats not imported by them - even though this boat was imported before 2004 when MC officialy started in OZ.